It takes two to tango. Is the tire the correct size for that rim?

(I didn't bother to see if that was mentioned above.)

650b.......:confused:

gp4000s

I do...It's called Canada! :fight:

Yes, it is.

Trusting that you know how to put tires on...yep, DT rims can be challenging but I haven't seen any that were not possible..build hundred 465/415 plus or minus.

I'd say warranty them.

BTW-I sell more Conti GP and such than any other tire and yes, you can put them onto a DT 415/465 rim, w/o tools, just palming it on. Tough but possible..for the below post.

Loose the GP4000 and get some vredesteins or Schwalbes.

I roll Conti tyres on DT rims using only my thumbs, all day. Man up.

Just to offer some moral support here: the same thing happened to me. I got a set of wheels built up with the 465s and for the life of me couldn't mount tires on them. I tried 3 or 4 different brands of tire (both new and used) and could not mount a tire without extreme exertion over a long period of time, to an extent that I wasn't comfortable with the idea of changing the wheel if I had gotten a flat.

The strangest part is that I had previously had another set of wheels with 465 rims and had no trouble mounting tires at all. I wonder if they slightly changed the dimensions of the rim in the past year or so. I know this doesn't offer any help, but at least you know you're not alone.

I have some old sharader valve 700 C wheels left over from the 80's with rims that seem a little more forgiving.....and it doesn't matter if I scratch them up with tire levers, ec. Can get cheap tubes at Walmart if necessary. I use them to stretch new tires. Helps me with problems you guys are describing.